Andesite ventefact, Atacama Desert, Chile


I collected this in the late 1990s while working with J. David Lowell on a consulting project in northern Chile.  It was thrilling to see, and collect, my first ventifact.  I had only read about them in physical geology textbooks, and never expected to see them in nature.  The ground was littered with them in places. As immovable objects sitting for long periods of time, they gradually wear away.  I chose carefully, looking for a ventefact that was small but well faceted, and of course smooth to the touch.  
     The locale was not too far from a spot where Dave Lowell discovered a mummified human body, which proved to have been “left” during the retreat of the Bolivian army in the late 1800s.  In the same area Dave reported stumbling upon thousands and thousands of boot prints, which were still recognizable on the ground, again a vestige of the retreating Bolivian army in the late 19th century.  No rain in quite a while!  Perfect place to find ventefacts!

Age & Formation
Mid-Tertiary andesitic volcanic rock, ~20Ma (?).